DE4328309A1 - Shock and / or impact absorbing component, in particular a front guard and method for its production - Google Patents

Description

The invention relates to an impact and / or impact sorbent, braced component, especially in the out design as a front protection bar, which is attached to a bracket supporting parts of a motor vehicle body attachable is, according to the preamble of claim 1. The Er The invention also relates to a method for producing a such component according to the preamble of the claim 16.

Such components are being used to an ever greater extent sets, with some car manufacturers already about this have gone, such components in the design to be fitted as standard to the vehicles as a front protection bar bring. These components have as a front guard or as Underride protection parts on the front of the motor vehicle especially with off-road or off-road vehicles not just the function, such parts of the motor vehicle body that is damaged by stone chips or the like can be protected. These parts are about in addition, in many cases already used others important functional parts of the vehicle, such as B. headlights fer, direction indicators, the radiator section, the engine, the Oil pan and the like effective against impact protect. This task also determines the stress Profile of such components or protective bars, which consequently must have high rigidity first, on the other However, their side should be designed so that they are supporting parts of the motor vehicle body with low vibration can be attached, so that there is an optima  Force flow from the front safety bar via the coupling place in the vehicle body.

From the German utility model G 91 05 739.6 is already a shock and / or shock absorbing component in the out design as a front guard according to the generic term of Claim 1 became known. This front protection bar compared to tubular structures, which has exclusively made of metal, a number of advantages and he draw net is particularly economically producible characterized in that it is optimal in the front from below variously designed or styled motor vehicles taking into account the respective coupling points the body on the one hand and the flow conditions on the other hand can be incorporated. In this known case there is the one lying inside the braced component Core from a metallic framework, and this core surrounding body is covered by an integral foam system educated. This has the advantage that the metal scaffolding with regard to choice of materials and shape can be raised that it is the individual Festig optimal requirements and power flow conditions fits. The integral foam system covering removes that individual metallic components fully visible, so that the outer appearance of the front guard bar is primarily shaped by the wrapping. It will open up hereby new possibilities of shaping and designs for the front protection bar, which also fits the individual len, existing boundary conditions with regard to Mounting options on the vehicle on the one hand, the order flow conditions on the other hand and finally also the Designs of the vehicle to be equipped can be adapted. So z. B. the main load-bearing component group pen of the metallic framework made of a different material or be formed with a different cross section than other areas of the front guard. The finished bracket is one of those, the modern styling of an off-road driving  no longer look at the stirrup's design, because the framework is covered with the integral foam system. The coating fulfills a stability-enhancing Function the other task, the front guard in that To integrate the "face" of the vehicle as well as possible. At the same time, the covering of the scaffolding acts as a vibration cushioning and thus the appearance of rattling and chatter noise towards.

With the increasing use of such components also the criteria and requirements for such elements te be changed. The automotive industry for of such components on the above weight criteria reduction, but still a high one Adaptability to different designs of the Front section of vehicles. There is also the fact that of such Components an absolute split even in severe accidents freedom from breakage is required, although after as before the external appearance of the shock and / or impact absorbing component such. B. the front guard gels optimally to the relevant part of the body customizable. In the course of minimizing costs the shock and / or impact absorbing components above it also the requirement of a particularly economical Chen manufacturability.

The invention is therefore based on the object of and / or impact-absorbing component, for example in the design of a front protection bar, according to the waiter Concept of claim 1 to create that still has the advantages of the generic state of the art, in addition, however, economically in large quantities cher is producible, the weight given Dimensional and breaking strength is reduced and the requirement to a splinter-free break even at low temperatures instruments should be met. There is another task  in a method of manufacturing such components create that even with large quantities through a distinguishes high economic efficiency.

This task is carried out with regard to the creation of the and / or impact absorbing component through the features of claim 1 and with respect to the method the features of claim 16 and the patent spell 18 solved.

The invention is based on the concept of shock absorbing the material with a full cross-section, to give an internal support corset that no longer only exists in a central area, but the area so inside the shock absorbing material is arranged that the largest possible surface ent stands over which a stiffening of the shock absorbing Material can be done. In this way, a ver equal to known solutions of much larger cross cut the strut to be stiffened by the Measure according to the invention even more effectively because the energy absorbing material in the structure of the core penetrates at least in certain areas. The single strut of the Component is not only in one area, but Overall, more impact-resistant and rigid, with the same early the advantage of a significant weight reduction in the Compared to conventional solutions with a metallic Framework results. By stiffening the jacket over one enlarged area of the cross-section can be seen above achieve breaking behavior that even at deep Temperatures do not tend to splinter, so that the ver Sweeping and safety requirements with Leich activity can be fulfilled. The coat can as before from a relatively elastic material are formed, so that an impact protection for Pedestrians to reduce the risk of injury represents is. Can be used as a method for producing the component  a primary form process is still used, which also economical production for large quantities guaranteed. The construction of the component according to the invention has compared to the prior art, the special procedural advantage that to achieve a high component stability only so-called "pure" materials, such as B. plastic the same Group or plastics from groups can be used that, if necessary, after grinding or shredding without further sorting intermediate steps a recycling ver driving can be fed. About that in the structure of the core penetrating at least in certain areas, energy dependent sorbent material can still be easily speed any desired shape adapted to the motor vehicle achieve compliance with road traffic regulations, as set out in EC directives. The Ener can also be encased in this core Set the absorption capacity well.

Advantageous embodiments of the invention are the subject of subclaims.

With the choice of the material for the non-metallic framework according to claim 2, the strength of the construction control particularly well by the flat or tubular fabric or scrim structure in the subject The strut to be stiffened is laid or oriented in this way and / or aligned to other stiffening structures will that the relevant stress profile of the strut is optimally taken into account.

Non-metallic frameworks in the form of a flat or tubular glass or fabric structure made of glass fa sern, Kevlar fibers (aramid fibers), carbon or Textile fibers can be created using suitable tools are preferably heated, and if necessary after implementation special process steps such. B. by a treatment  treatment with a suitable impregnating agent, such as. B. one Synthetic resin, to form a self-supporting scaffold component men, then in the production form of the front guard can be inserted. The framework molding is then in the shape by suitable holding means, for example in Form of lost plastic pens, the material of which preferably adapted the material of the other components is fixed in the production form and then with enclosed the energy absorbing material what for example by a casting process or by a Foaming process can happen. It has been shown that for a sufficient increase in strength of the braced Component already has a very low mass of non-metallic sufficient scaffolding, so that, for example, at Verwen of a GRP (glass fiber reinforced plastic) mat for the core structure and when foaming this mass with a polyurethane plastic system without any problems Possible recycling of the component manufactured in this way is.

With the training according to claim 4, the fracture and impact resistance of the component in a simple manner control, preferably with the measures according to Claim 6.

By appropriate treatment of the strength-increasing core the connection to the surrounding, impact absorbing material to thereby reduce the to strengthen the strengthening effect of the core structure.

The shock-absorbing material is advantageously made Made of a polyurethane-plastic system that can be cast or Foam mass may be present. With this mass can be with ease from the technical surveillance association (TÜV) comply with the prescribed radii (5 mm). About that In addition, there is a very high dimensional stability in the prescribed temperature range from -35 ° C to + 85 ° C,  as well as an absolutely splinter-free breaking property. With the sem plastic system can also the hardness in control a wide area, for example in the area between 50 and 100 SHORE.

The component can also be based entirely on nylon (Claim 9) be constructed, which leads to a further simplification recycling.

With the development of claim 10, the shock absorbing effect but also the breaking strength of the Continue to influence the component favorably.

If the scaffolding strands running through the individual struts related, there is a further simplification of the Manufacturing process, since the complete framework as a separate component, for example, can also be designed can.

Further advantageous embodiments are the subject of other subclaims. Below are based on schemati Scher drawings several embodiments of the inven explained in more detail. Show it:

Fig. 1 is a perspective view of a first Ausfüh approximate shape of the shock and impact absorbing construction partly in the form of a front guard;

Fig. 2-6 sectional views in sectional guides along the lines II-II, III-III, IV-IV, VV and VI-VI in Figure 1, with different, possible variants for the structure of the Kernge scaffolding are explained in the cuts;

Fig. 7 is a representation similar to Figure 1 of a wide ren embodiment of the front guard.

Fig. 8-13 sectional views of the struts of the front protection bracket according to FIG 7 with sectional guides along the lines VIII-VIII, IX-IX, XX, XI-XI, XII-XII and XIII-XIII in Fig. 7.

Fig. 14 is a schematic side view of a front guard with an attachment according to the invention on a longitudinal member of the vehicle;

Figure 15 is a section through a strut with a modified arrangement of the core structure.

Fig. 16 in an enlarged scale, the appearance of the base of the core skeleton forming scrim structure to illustrate the connection to the shock-absorbing mass surrounding it;

FIG. 17 shows a view similar to FIG. 15 of a further configuration of the strut cross section; and

Fig. 18 is an illustration of a section through the strut with a modified structure.

Fig. 1 shows a fully plastic front guard 20 in the form of a braced component. Some strut sections are designated with the reference characters Chen 22 to 30 . Fastening points of the front protection bar on the motor vehicle are provided with the reference number 32 . At these points are more stable, preferably metallic fasteners such as. B. cast in the form of threaded bushings, via which the attachment to the supporting parts of the motor vehicle body series then takes place.

Fig. 1 shows that it is a relatively complex spatial structure in the front guard, the individual struts 22 to 30 due to their location and orientation a different task and stress profile is assigned. All sections of the component have in common that they must have a high dimensional stability in a wide temperature range from about -40 ° C to + 85 ° C and a splinter-free fracture property with high strength. In order to be able to provide these properties in an economical manufacturing process, the front protection bar in the area of all struts 22 to 30 has a special structure (cf. FIGS. 2 to 6) with an inner core 34 in the form of a surface-covering scaffold which is used to form a full cross section is enclosed on all sides by an energy absorbing material 36 . The area-covering scaffold 34 is indicated in the figures with dashed lines. The dashed line outside the cross-section shows where the rear of the strut is located.

The framework of the core 34 consists of a non-metallic material which, at least in combination with the material 36 enclosing it, has high fracture toughness and high impact resistance. The core 34 is also such that the material 36 , which consists of an energy-absorbing material, preferably completely, but can at least partially penetrate into the structure of the core 34 . Finally, the materials for the core 34 and the mass 36 surrounding it are selected so that a type purity required for recycling is ensured, so that the entire front guard 20 can be fed to a recycling process after a grinding or shredding process without further separation steps.

In Figs. 2 to 6 show different configurations of the core are shown. However, it should be emphasized at this point that it is of course also possible to work with one and the same profile of the core 34 in the area of all struts. As can be seen in FIGS . 2 to 6, the non-metallic framework is formed, for example, by a flat tissue or gel structure 38 (see FIG. 16). This fabric or scrim structure consists of high-strength fibers 40 , which can be incorporated into the energy-absorbing material 36 so that a very intimate connection between the materials is preferably carried out over the entire surface. The arrows V in FIG. 16 indicate how the energy-absorbing mass 36 connects to the non-metallic fabric or scrim structure 38 , ie how the energy-absorbing mass encloses the core structure, as a result of which the stiffening effect can be optimized with minimal material consumption.

In Figs. 2 to 6 different spatial orientations of the core 34 are indicated, which Orien tierungen in each cross section the stress profile in question is matched. For example, FIG. 3 shows that the core 34 is displaced into the area of a vertical cross-sectional wing 42 which is later to carry the license plate of the motor vehicle. Since the strut 24 in the structure according to FIG. 1 will be subjected to very high loads in the event of an impact, the core 34 is additionally stiffened in this area by a further core structure 34 *. This effect can of course also be achieved by other measures, which will be explained later with reference to FIGS. 15 and 17.

The fibers 40 consist of high-strength, preferably tensile and stretch-resistant fibers, such as. B. glass fibers, hochfe most plastic fibers such. B. Kevlar fibers, ie aramid fibers with high resistance to stretch and great strength and flexibility, carbon fibers or textile fibers, and a mixture of the fibers can be used who can. Mats are preferably used, which can be brought into a specific profile shape under the influence of temperature. It is also possible to use tubular structures instead of flat fabric or fabric structures.

The shock absorbing material is preferably just if from a plastic system, for example, good results can be achieved with polyurethane plastic systems. Polyurethane systems can be manufactured by casting or foaming in multi-component technology, for example. A flow to the density over the cross section of the strut can be taken via the mass introduced into the mold, so that it is possible, for example, to provide a higher density in the outer region than in the inner region. However, it is equally possible to select the energy absorbing mass 36 from the plastic area of the polyamides. In both cases, the core structure not only results in high impact and shock resistance, but also an absolutely splinter-free breaking behavior.

Blank to 6 see Fig. 2, that it is Lich possible selbstverständ, to the core 34, 34 * in the interior of the solid profile formed by the ground 36 as desired spatially krüm men thereby influence the strength of the respective strut section.

Instead of or in combination with the flat or tubular fabric or scrim structure 38 - as shown in FIG. 6 - another frame in the form of a bundle of glass fibers and / or plastic fibers lying in the cross section of the strut 30 can also be used Aramid fibers (Kevlar fibers) and / or carbon fibers and / or textile fibers are used. These bundles are denoted by 44 in FIG. 6 and also in this case there is an at least partial penetration of the bundles 44 with which they close an energy absorbing material 36 . This Bün del 44 can also be both suitably shaped in the longitudinal direction and arranged relative to each other so that the desired strength profile is achieved.

The embodiment of FIGS . 7 to 13 is similar to that of FIGS . 1 to 6. Corresponding parts and components are therefore also provided with similar reference numerals, which are only preceded by a "1". The description can therefore be kept brief.

Deviating from the embodiment according to FIGS. 1 to 6, the non-metallic framework ( 134 ) is formed here by a tubular fabric or scrim structure, but it can also be combined with a fabric or scrim structure in the embodiment according to FIGS . 1 to 6 the. The hose structure can also be adapted to the relevant cross-section of the profile, which can be seen particularly clearly from FIGS . 8 and 9. Fig. 11 shows the combination of a flat and a tubular fabric or fabric structure.

In Figs. 15 and 17 other variations for the design of the core are indicated 234 and 334 respectively. The cross section of Fig mutandis. 17 has on (indicated by arrow F) the flip side, the side facing a corrugated shape to locally provide in this way an increased impact resistance.

In the embodiment according to FIG. 15, the tubular skeleton is added 334 to an impact-sensitive edge by a further flat structure 334 *.

In the manufacture of the component or front protection bar according to the invention, the core structure 34 is brought into a predetermined shape by suitable tools and possibly under the influence of temperature, as can be seen in FIGS. 2 to 6 and 8 to 13. For this purpose, the core structures can also be used with suitable means such. B. synthetic resin, this agent is then preferably selected from the materials that support an intimate connection with the residual material of the cross section. The preformed cores are then in the actual shape such. B. inserted an injection mold or foam mold and fixed in this form by, for example, lost retaining pins. In this state, the pouring or foaming with energy-absorbing material such as. B. a polyurethane plastic or a polyamide plastic.

However, the invention is not limited to this type of manufacture. Another layer structure as shown in FIG. 18 can also be used. Adhesive technology is used here, with core structures 434 A to 434 C located between the energy-absorbing sections 434 A to 434 C. The in this way ausgebil Dete component has such a strength with low weight that it can supply points 32 by a suitable positioning of the fastening provide complete impact protection. In this case, the core structure in the area of the fastening points 32 is selected and designed such that the power flow into the holders is favorable. In this way, as shown in FIG. 14, holders 50 and 60 can be used which have a controllable and a predetermined shock absorption behavior. For this purpose, the holder 50 uses a plastic shear element connected between the front protection bar 20 and the longitudinal beam 70 . A U is used in the holder 60 , the web 62 of which has a predetermined bending point 64 .

Claims (21)

1. Shock and / or impact-absorbing, braced construction part, in particular in the design as a front guard, which can be fastened to a supporting part of a motor vehicle body and has a braced inner core surrounded by a shock-absorbing material, thereby characterized in that the core ( 34 ; 134 ) is formed by a surface-covering scaffold made of non-metallic, at least in combination with the material ( 36 ; 136 ) enclosing it break-resistant and impact-resistant material and on all sides by an energy which at least partially penetrates into the structure of the core absorbent material is included, which is adapted to the material of the core ( 34 ; 134 ) such that it can be recycled together with the core without intermediate steps. 2. Component according to claim 1, characterized in that the non-metallic framework of a flat or tubular fabric or scrim structure ( 38 ) made of glass fibers, high-strength plastic fibers, such as. B. aramid fibers with high elongation resistance, great strength and flexibility and / or carbon (carbon) fibers and / or textile fibers is formed, the stress profile of the strut concerned in the interior of the strut cross-section ( 22 to 30 ; 122 to 130 ) is oriented accordingly. 3. Component according to claim 2, characterized in that the fabric or fabric structure is spatially curved. 4. Component according to one of claims 1 to 3, characterized in that the non-metallic framework at least one in cross-section of the strut ( 30 ) lying bundle ( 44 ) made of glass fibers and / or plastic fibers with high elongation resistance and / or large Strength and / or great flexibility such as. B. aramid fibers and / or carbon fibers and / or textile fibers, which in the interior of the struts cross-section oriented and / or aligned the stress profile of the strut ( 30 ). 5. Component according to claim 4, characterized in that the at least one bundle is corrugated in the longitudinal direction is. 6. Component according to claim 4 or 5, characterized in that a plurality of bundles ( 44 ) and / or flat and / or tubular fabric or fabric structures are in the strut cross-section ( 30 ), the relative position of the bundles ( 44 ) and / or flat fabric or fabric structures ( 34 ) to each other is adapted to the stress profile of the strut in question. 7. Component according to one of claims 2 to 6, characterized in that the frame is impregnated with a means by which the connection to the shock-absorbing material surrounding it ( 36 ; 136 ) is controllable. 8. Component according to one of claims 2 to 7, characterized characterized in that the shock absorbing material of a polyurethane-plastic system, preferably one Polyurethane foam system is formed. 9. Component according to one of claims 2 to 7, characterized characterized in that the shock absorbing material of a polyamide system, preferably a linear, aliphatic polyamide such as nylon is formed that also the basis for the fabric or fabric structure forms.   10. Component according to claim 8 or 9, characterized net that the shock absorbing material from a Plastic mass is formed in the glass fibers and / or plastic with high elongation resistance or great strength such. B. Aramid fibers incorporated are. 11. The component according to claim 10, characterized in that the length of the fibers in the range between 0.2 and 0.6 mm lies. 12. Component according to one of claims 1 to 11, characterized characterized that the framework is preformed. 13. Component according to one of claims 1 to 12, characterized in that the individual struts ( 22 to 30 ) are continuous scaffolding strands. 14. Component according to one of claims 1 to 13, characterized characterized in that the shock absorbing material of a foam mass is formed. 15. Component according to one of claims 1 to 13, characterized characterized in that the shock absorbing material of a casting compound is formed. 16. Process for producing a shock and / or impact-absorbing, braced component after a of claims 1 to 15, characterized by the following Process steps: Forming the scaffold from non-metallic, at least in combination with the enclosing material, break-resistant and impact-resistant material into a coherent soul structure, preferably under the influence of temperature and, if necessary, after carrying out an impregnation process with one of the inner and / or the bond to the environment and / or the Dimensional control agent;
Fixing the scaffold in a form using lost holding means; and
Pouring around or framing the scaffold with a mass which in the solidified state has impact and / or impact absorbing properties. 17. The method according to claim 16, characterized in that that encapsulating the scaffold with a multi-component plastic system. 18. A method for producing a shock-absorbing and / or impact-absorbing, braced component according to one of claims 1 to 15, characterized by the following method steps:
Reshaping the framework from non-metallic, at least in combination with the material enclosing it, break-resistant and impact-resistant material; and
Surround the structure in layers with shock-absorbing material until the desired cross-section of the strut in question is reached. 19. The method according to claim 18, characterized in that between the layers of shock absorbing Material further layers of tough and / or impact-resistant material. 20. Bracket for a front protection bar, in particular according to one of claims 1 to 19, with retaining elements anchored in the front protection bracket, such as. B. plates, pins or the like, characterized in that the holding elements are attached to shock-absorbing elements ( 50 , 60 ) with predetermined deformation and / or shock absorption behavior.